1. Field of the Invention
The present invention relates to a production apparatus and a production method for producing a bent portion of a multi-channel tube, which is provided with partitions therein so that plural flows may pass therethrough.
2. Description of the Related Art
For conducting fluids, various types of pipes are utilized in various machines. Japanese Utility Model Patent Examined Publication No. 64-006465 discloses an art for combining plural pipes into a multi-channel tube.
Such pipes utilized in machines are often bent in certain necessities. In a case of single-hole pipes, bending is not a troublesome work. A mandrel is inserted into a pipe so as to prevent unfavorable deformation and then smooth bending can be achieved. However, in a case of the multi-channel tubes, bending may be often troublesome since the mandrel is not fully effective to prevent unfavorable deformation. For example, partitions inside of the multi-channel tube may unfavorably deform and, in certain cases depending on a bending direction, even an outer wall thereof may deform in a denting or rumpling shape.